Mathieu is ten years old. Summer returns, he will find all his pals coming to spend their holidays in the small seaside resort where he lives with his father, entrepreneur with funeral pomp. The small band will re-form as every summer to make... the worst nonsense.That summer, Mathieu view Nadine, the mother of his worst enemy Robert, went into head for a child to marry the father of Mathieu. It must at all costs prevent this disaster! The imagination of the buddies is used: simply administer Nadine of contraceptive pills without his knowledge... And it is there that the trouble will begin for all.